The present invention relates to novel prostacyclin analogs and intermediates for their production. Most particularly, the present invention provides 2,5-inter-o-phenylene-3,4-dinor-6,9.alpha.-epoxy-6.beta.-PGF.sub.1 compounds. The preparation and use of the novel compounds described herein is incorporated here by reference from U.S. Pat. No. 4,281,113.